具有谐波抑制能力的链式STATCOM控制方法的研究

发布时间：2018-03-10 13:30

本文选题：链式静止同步补偿器　切入点：滑窗迭代离散傅立叶变换　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：近些年,由于电网日趋复杂,人们投入大量的非线性、冲击性负载,配网中产生的无功源、谐波源导致电能质量问题越来越严重。在提高电能质量方面,链式静止同步补偿器(static synchronous compensator, STATCOM)不仅能够动态实时对无功电流进行补偿,还可以结合有源电力滤波技术进行谐波抑制。因其动态响应快、模块化设计、高可靠性等诸多优点,得到广泛的工程应用。随着不断的深入,其中链式STATCOM的控制方法成为研究热点。本文详细分析了链式STATCOM的主电路拓扑结构及基本原理,对数学模型进行理论推导。为使链式STATCOM具备谐波抑制能力,采用同步旋转坐标变换及滑窗迭代离散傅立叶变换相结合的指令电流检测方法,仿真及实验均验证了该方法正确可行,能精确的检测到负载的无功及谐波电流。对于电流跟踪控制方法,传统的PI控制器对特定次谐波的补偿能力难以达到控制目标,本文采用PI控制与矢量比例积分(vector proportion integral,VPI)控制相结合的电流跟踪控制,分别对传统PI控制及所采用的PI-VPI控制进行仿真及结果分析。经过对比,证明了 PI-VPI控制效果更好。主电路H桥结构的直流侧电容电压能否平衡直接影响着系统的稳定运行,本文采取有功矢量叠加的控制方法实现均压控制。当补偿无功和抑制谐波的容量需求超出装置设计容量时,需要采取有效的限流控制方法以满足电网电能质量的要求。文中针对实际运行中出现指令电流超出装置额定电流的状况,提出了结合目标功率因数法的优先级限流控制方法,该方法在满足系统功率因数的情况下同时提高谐波抑制能力。在MATLAB/Simulink中搭建仿真模型,进行结果分析证明了上述控制方法的可行性和有效性。在链式STATCOM的实验平台上,实现DSP及FPGA的联合软件控制。在该实验平台上对本文所采用的各种控制方法进行实验验证,通过实验结果分析,验证了上述控制方法的正确性和有效性。
[Abstract]:In recent years, due to the increasingly complex power network, people put in a large number of nonlinear, impact load, reactive power sources generated in the distribution network, harmonic sources lead to more and more serious power quality problems. The chain static synchronous compensator can not only compensate reactive current dynamically in real time, but also suppress harmonics in combination with active power filter, because of its advantages of fast dynamic response, modular design, high reliability and so on. It has been widely used in engineering. With the development of STATCOM, the control method of chain STATCOM has become a hot topic. The topology and basic principle of main circuit of chain STATCOM are analyzed in detail in this paper. The mathematical model is derived theoretically. In order to make the chain STATCOM possess the ability of harmonic suppression, the instruction current detection method combining synchronous rotation coordinate transform and sliding window iterative discrete Fourier transform is adopted. The simulation and experiments show that the method is correct and feasible, and can accurately detect the reactive power and harmonic current of load. For the current tracking control method, the traditional Pi controller is difficult to achieve the control goal of compensating the specific subharmonics. In this paper, the traditional Pi control and the PI-VPI control are simulated and the results are analyzed by using the current tracking control which combines Pi control with vector integral proportion VPI control. It is proved that the control effect of PI-VPI is better. Whether or not the capacitance voltage of the DC side of the H-bridge structure of the main circuit can balance directly affects the stable operation of the system. In this paper, the active power vector superposition control method is adopted to realize the voltage sharing control. When the capacity of compensating reactive power and suppressing harmonics exceeds the designed capacity of the device, Effective current limiting control method is needed to meet the requirement of power quality. In view of the situation that the instruction current exceeds the rated current of the device in actual operation, a priority current limiting control method combined with the target power factor method is proposed in this paper. This method can improve the harmonic suppression ability while satisfying the power factor of the system. The simulation model is built in MATLAB/Simulink, and the results show that the control method is feasible and effective. The joint software control of DSP and FPGA is realized. On this experimental platform, various control methods used in this paper are verified experimentally, and the correctness and effectiveness of the above control methods are verified by the analysis of experimental results.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761.12

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